Device and method for monitoring abrasion loss of brake friction plate

Abstract

The invention discloses a brake friction plate abrasion loss monitoring device and method, and relates to the technical field of engineering machinery, the brake friction plate abrasion loss monitoring device comprises a monitoring mechanism, the monitoring mechanism is installed on a transition disc of a brake shell, and the monitoring end of the monitoring mechanism penetrates through the brake shell to abut against the end face of a piston of a brake; when the piston presses the buffer disc under the action of brake hydraulic oil, brake torque abrasion is generated between the buffer disc and the friction plate, and the change of the extension amount of the monitoring mechanism reflects the abrasion amount. By the adoption of the displacement sensor, an alarm can be triggered after the abrasion limit is reached, the abrasion value of the friction plate can be monitored in real time, a reference basis is provided for preventive maintenance of the brake, and the monitoring device has the advantages of being small in size, small in original structure change, good in compatibility, high in measurement precision and the like.

Description

Technical Field

[0001] The invention relates to the technical field of engineering machinery, and in particular to a device and method for monitoring the wear of a brake friction plate. Background Art

[0002] Wet disc brakes have the advantages of large braking torque, easy maintenance, and long service life, and are widely used in the braking system of mining dump trucks. The friction pad is the source of the braking force generated by the wet disc brake, and its wear state determines the reliability of the entire braking system. Therefore, it is very necessary to check the wear of the wet disc brake friction pad.

[0003] At present, the wear of the friction plate is mainly measured manually at the measuring hole. During the measurement, some cooling oil needs to be released, otherwise it is easy to cause the cooling oil to overflow, and the measurement is time-consuming and laborious. Some wet disc brakes are also equipped with wear detection sensors, but they all use travel switches. Only when the friction plate reaches the set wear limit can the travel switch be triggered to send out an alarm signal. Before the wear limit is reached, the travel switch does not work, the specific wear amount cannot be measured, and preventive maintenance cannot be achieved. Summary of the invention

[0004] The object of the present invention is to provide a brake friction pad wear monitoring device and method to solve the problems in the current market raised by the above background technology.

[0005] To achieve the above object, the present invention provides the following technical solution: a brake friction pad wear monitoring device, comprising: A monitoring mechanism, wherein the monitoring mechanism is mounted on a transition plate of a brake housing, and a monitoring end of the monitoring mechanism penetrates through the brake housing and abuts against an end face of a brake piston; When the piston presses the buffer disk under the action of the brake hydraulic oil, the buffer disk and the friction plate generate braking torque wear, and the change in the extension amount of the monitoring mechanism reflects the amount of wear.

[0006] Preferably, the monitoring mechanism comprises a displacement sensor and an indicator rod mounted on the displacement sensor and abutting against the end surface of the piston.

[0007] Preferably, the indicator rod includes a basic section plugged into the displacement sensor to cooperate with displacement monitoring, a reset spring is sleeved on the basic section and one end thereof abuts against a spring seat provided on the end face of the outer shell of the displacement sensor, a baffle is installed on the other end of the reset spring, the end of the basic section passes through the baffle, and the baffle is limited by threading the extension section to the basic section.

[0008] Preferably, the brake housing is provided with a through hole for the extension section to pass through and a spring cavity for the elastic movement of the return spring.

[0009] Preferably, the displacement sensor is further provided with an external thread for connecting to the transition disc of the brake housing, a sealing groove is provided at the connecting surface between the displacement sensor and the transition disc, and a sealing ring is installed in the sealing groove to seal between the displacement sensor and the transition disc.

[0010] Preferably, a hexagonal section is also provided on the outer circle of the displacement sensor.

[0011] Preferably, the sealing pressure between the displacement sensor and the transition plate is ≥6 bar.

[0012] Preferably, the difference between the diameter of the extended section and the diameter of the through hole is 0.5 mm-1.0 mm.

[0013] Preferably, the diameter of the spring cavity is at least 5 mm larger than the diameter of the baffle.

[0014] Preferably, the depth of the spring cavity is the maximum wear amount of the friction plate plus 3 mm.

[0015] A method is used for the above-mentioned brake friction pad wear monitoring device, and the monitoring steps are as follows: S1: The displacement sensor monitors the extension amount of the indicator rod and outputs a current signal, and the conversion circuit converts the current signal into a piston displacement value A; S2: The brake pressure P acting on the brake piston is measured by the pressure sensor of the brake circuit. When the brake pressure P reaches the preset brake action pressure P0, the piston presses the friction plate tightly and the piston stroke reaches the maximum. The difference between the piston displacement value A at this time and the initial piston displacement A0 is the friction plate wear Δ; S3: The friction plate wear amount Δ obtained in S2 is fed back to the display unit for display, and the controller logic judgment unit compares the actual wear value Δ with the set wear limit Δmax. When the actual wear value Δ exceeds the limit Δmax, a wear alarm is triggered, thereby displaying the wear alarm on the display unit and triggering a sound alarm at the same time.

[0016] Compared with the prior art, the present invention has the following beneficial effects: The present invention adopts a displacement sensor, which can not only trigger an alarm after reaching the wear limit, but also monitor the friction plate wear value in real time, providing a reference basis for preventive maintenance of the brake. The monitoring device has the advantages of small size, few changes to the original structure, good compatibility, and high measurement accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The accompanying drawings are part of the present invention and are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention, but do not constitute an improper limitation of the present invention. Obviously, the accompanying drawings described below are only some embodiments. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without creative work.

[0018] Figure 1 It is a schematic cross-sectional structure diagram of a brake friction pad wear monitoring device of the present invention; Figure 2 This is a schematic diagram of the cross-sectional structure of a sensor of a brake friction pad wear monitoring device of the present invention; Figure 3 This is a schematic diagram of the connection structure of an indicator rod of a brake friction pad wear monitoring device of the present invention; Figure 4 This is a schematic diagram of the cross-sectional structure of a brake housing of a brake friction pad wear monitoring device according to the present invention; Figure 5 This is a schematic diagram of the connection structure between the buffer plate steel sheet and the brake housing of a brake friction plate wear monitoring device of the present invention; Figure 6 The present invention is a flow chart of a brake friction pad wear monitoring device and a brake friction pad wear monitoring method.

[0019] In the figure: 1. displacement sensor; 101. spring seat; 102. external thread; 103. back-cut groove; 104. sealing groove; 105. hexagonal section; 2. sealing ring; 3. transition plate; 4. indicator rod; 401. base section; 402. return spring; 403. baffle; 404. extension section; 5. brake housing; 501. through hole; 502. spring cavity; 6. piston; 7. buffer plate; 8. friction plate; 9. steel plate. DETAILED DESCRIPTION

[0020] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0021] See also Figure 1-Figure 6 , a brake friction pad wear monitoring device, such as Figure 1As shown, it includes: a monitoring mechanism, which is installed on the transition plate 3 of the brake housing 5, and the monitoring end of the monitoring mechanism passes through the brake housing 5 and abuts against the end face of the brake piston 6; when the piston 6 presses the buffer plate 7 under the action of the brake hydraulic oil, the buffer plate 7 and the friction plate 8 produce braking torque wear, and the change in the extension amount of the monitoring mechanism reflects the wear amount.

[0022] In a specific implementation, the monitoring mechanism includes a displacement sensor 1 and an indicator rod 4 mounted on the displacement sensor 1 and abutting against the end surface of the piston 6 .

[0023] As a further note: Combination Figure 2 and Figure 3 As shown, the displacement sensor 1 adopts the differential inductance principle to convert mechanical quantity into analog current signal output, and the outer shell of the displacement sensor 1 is a fully sealed shell. A spring seat 101 is provided on the end surface of the shell of the displacement sensor 1, and an annular groove is provided to provide installation space and limit the reset spring 402. The indicator rod 4 includes a basic section 401 plugged into the displacement sensor 1 to cooperate with displacement monitoring, and the basic section 401 is sleeved with a reset spring 402 and one end is against the spring seat 101 provided on the end surface of the shell of the displacement sensor 1. The other end of the reset spring 402 is installed with a baffle 403, thereby providing a reset force for the indicator rod 4; the end of the basic section 401 passes through the baffle 403, and the baffle 403 is limited by threading the extension section 404 with the basic section 401.

[0024] As a further limitation, the end of the extended section 404 has an arc-shaped cross-section, which allows the extended section 404 to fit tightly against the piston 6, avoiding a gap between the two and improving measurement accuracy. At the same time, the stroke of the reset spring 402 is sufficient to ensure that when the brake piston 6 is pressed to the maximum stroke, the extended section 404 can still resist the end face of the piston 6.

[0025] When the stroke of the piston 6 and the amount of wear of the friction plate 8 are different, this can be achieved by replacing the extension section 404 of different lengths, while the base section 401, the return spring 402, and the baffle 403 do not need to be changed, which can improve the versatility of parts and facilitate standardization.

[0026] The displacement sensor 1 is provided with an external thread 102 for connecting to the transition disc 3 of the brake housing 5. In order to facilitate the processing of the external thread 102, a back-off groove 103 is provided. A sealing groove 104 is provided at the connection surface between the displacement sensor 1 and the transition disc 3. A sealing ring 2 is installed in the sealing groove 104 to seal between the displacement sensor 1 and the transition disc 3 to ensure that the brake cooling oil in the brake housing 5 does not leak. The sealing pressure between the displacement sensor 1 and the transition disc 3 is ≥6 bar. A hexagonal section 105 is also provided on the outer circle of the displacement sensor 1, so that the displacement sensor 1 can be operated with a wrench during installation.

[0027] like Figure 4 As shown, the brake housing 5 is provided with a through hole 501 for the extension section 404 to pass through and a spring cavity 502 for the elastic movement of the return spring 402. The through hole 501 and the extension section 404 are clearance-fitted.

[0028] The diameter D1 of the through hole 501 and the diameter d1 of the extension section 404 satisfy the relationship D1=d1+(0.5mm-1.0mm). When the extension section 404 is subjected to abnormal bending force, the extension section 404 will contact the outer wall of the through hole, and the bending rigidity of the extension section 404 is improved.

[0029] The inner diameter D2 of the spring cavity 502 and the outer diameter d2 of the baffle 403 satisfy the relationship D2≥d2+5mm.

[0030] The depth dimension of the spring cavity 502 is the maximum wear amount of the friction plate 8 plus 3 mm.

[0031] It should be noted that: in one embodiment, the displacement sensor 1 is installed on the transition plate 3 through the external thread 102, and the extended section 404 is pressed against the end face of the piston 6 under the action of the return spring 402. The piston 6 presses the buffer plate 7 back under the action of the brake hydraulic oil, and the buffer plate 7 further presses the friction plate 8 to generate a braking torque. When the friction plate 8 is worn, its thickness value decreases, and the extension amount of the extended section 404 changes, thereby reflecting the wear amount of the friction plate 8.

[0032] like Figure 5 As shown, in this embodiment, the outer diameters of the buffer disc 7 and the steel sheet 9 are provided with external spline teeth, and the inner diameter of the brake housing 5 is provided with internal spline grooves. The buffer disc 7 and the steel sheet 9 are connected to the brake housing 5 through splines. The piston 6 and the buffer disc 7 can only move axially and cannot rotate circumferentially, thereby ensuring that the piston 6 and the extension section 404 do not rotate relative to each other, avoiding wear of the head of the extension section 404 and causing measurement errors. The friction plate 8 is connected to the wheel hub through an internal spline to transmit the friction torque to the wheel.

[0033] like Figure 6 As shown, the monitoring steps of the brake friction pad wear monitoring device are as follows: S1: The displacement sensor 1 monitors the extension of the indicator rod 4 and outputs a current signal, and the conversion circuit converts the current signal into a displacement value A of the piston 6; S2: The brake pressure P acting on the brake piston 6 is measured by the pressure sensor of the brake circuit. When the brake pressure P reaches the preset brake action pressure P0, the piston 6 presses the friction plate 8 and the piston 6 reaches the maximum stroke. The difference between the displacement value A of the piston 6 at this time and the initial displacement A0 of the piston 6 is the wear amount Δ of the friction plate 8; S3: The wear amount Δ of the friction plate 8 obtained in S2 is fed back to the display unit for display, and the controller logic determination unit compares the actual wear value Δ with the set wear limit Δmax. When the actual wear value Δ exceeds the limit Δmax, a wear alarm is triggered, thereby displaying the wear alarm on the display unit and triggering a sound alarm at the same time.

[0034] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A brake friction pad wear monitoring device, characterized in that: include: A monitoring mechanism, the monitoring mechanism being mounted on a transition plate (3) of a brake housing (5), the monitoring end of the monitoring mechanism penetrating the brake housing (5) and abutting against an end surface of a brake piston (6); When the piston (6) presses the buffer disc (7) under the action of the brake hydraulic oil, the buffer disc (7) and the friction plate (8) generate braking torque wear, and the change in the extension amount of the monitoring mechanism reflects the amount of wear.

2. The brake friction pad wear monitoring device according to claim 1, characterized in that: The monitoring mechanism comprises a displacement sensor (1) and an indicator rod (4) mounted on the displacement sensor (1) and abutting against an end surface of the piston (6).

3. The brake friction pad wear monitoring device according to claim 2, characterized in that: The indicating rod (4) comprises a base section (401) inserted into the displacement sensor (1) for cooperating with displacement monitoring, a return spring (402) is sleeved on the base section (401) and one end of the base section (401) abuts against a spring seat (101) provided on an end surface of a housing of the displacement sensor (1), a baffle (403) is mounted on the other end of the return spring (402), a distal end of the base section (401) passes through the baffle (403), and the baffle (403) is limited by threading an extension section (404) to the base section (401).

4. The brake friction pad wear monitoring device according to claim 3, characterized in that: The brake housing (5) is provided with a through hole (501) through which the extension section (404) passes, and a spring cavity (502) for elastic movement of the return spring (402).

5. The brake friction pad wear monitoring device according to any one of claims 2 to 4, characterized in that: The displacement sensor (1) is also provided with an external thread (102) for connecting to the transition plate (3) of the brake housing (5); a sealing groove (104) is provided at the connection surface between the displacement sensor (1) and the transition plate (3); a sealing ring (2) is installed in the sealing groove (104) to seal between the displacement sensor (1) and the transition plate (3).

6. The brake friction pad wear monitoring device according to claim 5, characterized in that: The outer circle of the displacement sensor (1) is also provided with a hexagonal section (105).

7. The brake friction pad wear monitoring device according to claim 5, characterized in that: The sealing pressure between the displacement sensor (1) and the transition plate (3) is ≥ 6 bar.

8. The brake friction pad wear monitoring device according to claim 4, characterized in that: The difference between the diameter of the extended section (404) and the diameter of the through hole (501) is 0.5 mm to 1.0 mm.

9. The brake friction pad wear monitoring device according to claim 4, characterized in that: The diameter of the spring cavity (502) is at least 5 mm larger than the diameter of the baffle (403).

10. The brake friction pad wear monitoring device according to claim 4, characterized in that: The depth dimension of the spring cavity (502) is the maximum wear amount of the friction plate (8) plus 3 mm.

11. A method for the brake friction pad wear monitoring device according to any one of claims 1 to 10, wherein the monitoring steps are as follows: S1: The displacement sensor (1) monitors the extension amount of the indicator rod (4) to output a current signal, and the conversion circuit converts the current signal into a displacement value A of the piston (6); S2: The brake pressure P acting on the brake piston (6) is measured by a pressure sensor in the brake circuit. When the brake pressure P reaches a preset brake action pressure P0, the piston (6) presses the friction plate (8) and the piston (6) reaches a maximum stroke. The difference between the displacement value A of the piston (6) at this time and the initial displacement A0 of the piston (6) is the wear amount Δ of the friction plate (8); S3: The wear amount Δ of the friction plate (8) obtained in S2 is fed back to the display unit for display, and the controller logic determination unit compares the actual wear value Δ with the set wear limit Δmax. When the actual wear value Δ exceeds the limit Δmax, a wear alarm is triggered, thereby displaying the wear alarm on the display unit and triggering an audible alarm.

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